Self-powered sensor for rotating speed monitoring of rotating machinery and its application in intelligent toolholder of CNC machine tools

Addressing the critical demand for high-precision, highly integrated, and durable rotational speed sensors capable of withstanding complex operating conditions in rotating machinery, we propose an innovative ball vibration based triboelectric nanogenerator (VS-TENG) for rotational monitoring of rotating machinery, and systematically construct the motion control equation system of VS-TENG. The VS-TENG innovatively harnesses the rotational energy of machinery to evoke vibrations within its internal spheres, thereby activating the device to generate electrical signals. The integration of variational mode decomposition (VMD) enables effective filtration of noise and non-essential modal components, facilitating the isolation and analysis of triboelectric signature signals. By monitoring the voltage frequency's variation directly correlated to rotational speed, the sensor achieves both accurate measurement and real-time monitoring. The proposal of VS-TENG overcomes the problem of traditional sensors being prone to wear and accuracy degradation under high-speed rotation conditions and demonstrates significant durability and high-precision characteristics. Experimental validation across a wide rotational speed range from 50 to 1600 rpm underscores its performance, with a detection error rate consistently below 0.505 %. Notably, even after sustained operation for 50 h, the VS-TENG maintains a stable electrical output, underscoring its long-term reliability. This achievement is expected to provide stronger technical support for the intelligent and efficient operation and maintenance of rotating machinery.